/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.dubbo.config.spring.status;

import org.apache.dubbo.common.extension.Activate;
import org.apache.dubbo.common.logger.Logger;
import org.apache.dubbo.common.logger.LoggerFactory;
import org.apache.dubbo.common.status.Status;
import org.apache.dubbo.common.status.StatusChecker;
import org.apache.dubbo.config.spring.extension.SpringExtensionFactory;

import org.springframework.context.ApplicationContext;
import org.springframework.context.Lifecycle;

import java.lang.reflect.Method;

/**
 * SpringStatusChecker
 */
@Activate
public class SpringStatusChecker implements StatusChecker {

  private static final Logger logger = LoggerFactory.getLogger(SpringStatusChecker.class);

  @Override
  public Status check() {
    ApplicationContext context = null;
    for (ApplicationContext c : SpringExtensionFactory.getContexts()) {
      if (c != null) {
        context = c;
        break;
      }
    }

    if (context == null) {
      return new Status(Status.Level.UNKNOWN);
    }

    Status.Level level = Status.Level.OK;
    if (context instanceof Lifecycle) {
      if (((Lifecycle) context).isRunning()) {
        level = Status.Level.OK;
      } else {
        level = Status.Level.ERROR;
      }
    } else {
      level = Status.Level.UNKNOWN;
    }
    StringBuilder buf = new StringBuilder();
    try {
      Class<?> cls = context.getClass();
      Method method = null;
      while (cls != null && method == null) {
        try {
          method = cls.getDeclaredMethod("getConfigLocations", new Class<?>[0]);
        } catch (NoSuchMethodException t) {
          cls = cls.getSuperclass();
        }
      }
      if (method != null) {
        if (!method.isAccessible()) {
          method.setAccessible(true);
        }
        String[] configs = (String[]) method.invoke(context, new Object[0]);
        if (configs != null && configs.length > 0) {
          for (String config : configs) {
            if (buf.length() > 0) {
              buf.append(",");
            }
            buf.append(config);
          }
        }
      }
    } catch (Throwable t) {
      logger.warn(t.getMessage(), t);
    }
    return new Status(level, buf.toString());
  }

}
